May 6 2011:
Humans have always been quick to adapt to and environment. I'm thinking more along the lines of physical development.

In nature if something cannot fend for itself due to a genetic deformity it does not survive and cannot reproduce. This genetic deformity is removed from the chain through natural selection, but we as humans don't do this! We welcome and support people who have disabilities and we do make families with them and we continue to grow without any concern for natural selection.

(Before I'm accused of being an insensitive fool i would like to note that i have a partner with a genetic disease and i have no issue with the significant lack of natural selection)

May 9 2011:
I think that the domestication of animals might be another good way to illustrate the point.
In domesticating animals we have not stopped their evolution so much as used the "laws" or "rules" of evolution to guide the adaptations of those animals in a particular way. We "select" animals with desired traits and breed them so that those genes will spread at a higher frequency into the gene pool and eliminate undesirable traits by culling those individuals out of the gene pool.
By controlling our environment we are merely domesticating ourselves.Though, we are less intentional with the traits that we are selecting for, but at some point I'm sure humanity will decide to take a more proactive approach to our own domestication, but as things stand now, eugenics has a very bad name and is not actively pursued by any major legitimate program.

To use a null hypothesis: for evolution to not happen, these four things would need to not happen. which is not the case. Evolution has not stopped.
For those of you who would question the validity of natural selection still being in effect you should first have a proper understanding of what it is. Some of the most common types of natural selection are: survival of the fittest meaning: survival and procreation of those individuals most best adapted to the environment. another strong form of natural selection is Sexual selection which is the proliferation of those genes selected by mating preferences and often has a great effect on the physical traits of a species, for instance peacock feathers. There are some other types but I think the point is illustrated.

Our ability to control or effect our environment does not stop evolution. If we can cure a disease or prevent symptoms that might otherwise remove an individual from a gene pool, it just means that we are changing the selective pressures of natural selection. Those who have access to healthcare can now proliferate their genes into the gene pool but that doesn't mean evolution isn't in operation, it just means that the adaptation being selected for isn't health but rather access to medicine.

May 7 2011:
about time there was a true thought provoking question thrown out.

An extremely interesting idea. we, as humans are one of the worlds first species to, like u mention, welcome and support the less able and elderly.

if evolution is fueled by species adapting in order to ensure the continuation of their species, with humans interfering in the way we do, are we slightly or completely effecting human evolution? I shall ponder this idea a lot more indeed.

many academics point to current and future human evolution to be with technological advancements through the increasing power and usage of the brain. im always astonished looking over the advancements in technology in the last century or two and bewildered about what the next century will contain. perhaps that is where we are not evolving.

back to the original idea, again you make a sound point. i do wonder if we are affecting out physical evolution by not allowing ourselves to be old and ill.

May 6 2011:
it is old science that evolution is fast if the environment changes fast. human environment changed greatly since the beginning of civilization, so we expect evolution to speed up, not slow down. and evidence indicates that it is indeed what's happening.

true, the selection pressure decreased or vanished in many areas, like being resistant to infections or some other illnesses. but the selection pressure in general is higher than ever. think about it that way: how many children one has, is completely independent of one's genes? surely not. and even the slightest influence counts in the long run.

of course, while evolution is faster than ever, it is indeed very slow compared to the recent non-genetic changes in society. it gives the false impression that genetic evolution stopped.

May 6 2011:
It's possible rather the other way.
Why you think process of evolution should be stopped or slowed down when we are bringing continuous quick changes in environment ?
Slowed down or stopped evolution means we should lose adaptability quicker, theoretically and logically. Do you feel that's the case?